Particle separators for turbomachines and method of operating the same

ABSTRACT

A particle separator includes a separator body in a primary fluid passageway of a machine. The primary fluid passageway includes one or more bleed holes through which a diverted portion of the fluid flowing in the primary fluid passageway toward a volume of the machine is diverted into an auxiliary flow passageway that bypasses the volume and directs the diverted portion of the fluid toward one or more other components of the machine. The separator body is coupled with the inner wall and/or outer wall of the primary fluid passageway. The separator body includes an upstream edge positioned to separate at least some particles carried by the fluid from the fluid as the diverted portion of the fluid bends around and flows over the at least one upstream edge of the separator body and into the auxiliary flow passageway.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.16/186,834 (filed 12 Nov. 2018), which is a continuation-in-part of U.S.patent application Ser. No. 14/940,251 (filed 13 Nov. 2015, now U.S.Pat. No. 10,612,465). The entire disclosures of these applications areincorporated herein by reference.

FIELD

The field of the disclosure relates generally to a gas turbine engineand, more particularly, to a particle separator for turbomachines andmethod of enhancing particle removal in a turbomachine.

BACKGROUND

At least some known turbomachines, i.e., gas turbine engines, compressair via a plurality of rotatable compressor blades and ignite a fuel-airmixture in a combustor to generate combustion gases that are channeledthrough rotatable turbine blades via a hot gas path. Such knownturbomachines convert thermal energy of the combustion gas stream tomechanical energy used to generate thrust and/or rotate a turbine shaftto power an aircraft. Output of the turbomachine may also be used topower a machine, for example, an electric generator, a compressor, or apump.

Many of these known turbomachines include internal cooling air circuitsfor high temperature components. Air is drawn into the turbomachineduring operation, channeled through the compressor, and into the coolingair circuits, thereby cooling selective components. Turbomachinesfrequently encounter conditions in which a high level of sand and/orparticulate matter exists, such as deserts and air-polluted regions.When sand and/or particles enter the cooling air circuits, the particlesaccumulate around small features such as rims, film cooling holes, andturbulators. This accumulation of particles decreases the effectivenessof cooling the high temperature components. Cooling air is preventedfrom directly contacting heat transfer surfaces of the high temperaturecomponents. Additionally, alteration of high temperature componentgeometry and/or blocking film cooling holes by the particles alsodecreases the effectiveness of cooling the high temperature components.As a result, the anticipated service life of turbine components may beshortened, thereby resulting in unplanned engine downtime and increasedmaintenance costs.

BRIEF DESCRIPTION

In one embodiment, a particle separator includes a separator bodyconfigured to be disposed in a primary fluid passageway of a machinethat directs a particle-carrying fluid along a flow path in the primaryfluid passageway toward a volume of the machine. The primary fluidpassageway located between opposing first and second walls. In oneembodiment, these walls circumferentially extend around or encircle acenterline of the machine. Alternatively, these walls oppose each otherwithout circumferentially extending around or encircling a centerline ofthe machine. For example, these walls may not be disposed in a rotatingmachine or a machine having a centerline. The primary fluid passagewayincludes one or more bleed holes through which a diverted portion of thefluid flowing in the primary fluid passageway is diverted into anauxiliary flow passageway that bypasses the volume and directs thediverted portion of the fluid toward one or more components of themachine that are outside of the volume of the machine. The separatorbody extends along the flow path from an upstream end that is configuredto be coupled with the inner wall of the primary fluid passageway. Theseparator body includes at least one upstream edge positioned toseparate at least some particles carried by the fluid from the fluid asthe diverted portion of the fluid bends around and flows over the atleast one upstream edge of the separator body and into the auxiliaryflow passageway via the one or more bleed holes while a non-divertedportion of the fluid continues to flow along the flow path in theprimary fluid passageway.

In one embodiment, a method includes establishing a fluid flow ofparticle-laden fluid in a primary fluid passageway of a machine that isdefined by opposing first and second walls. These walls maycircumferentially extend around or encircle the centerline of a machinehaving one or more rotating component. Alternatively, the walls may notcircumferentially extend around or encircle the centerline of such amachine, the machine may not have a centerline, or the machine may nothave a rotating component. The method also can include filtering a firstportion of the particle-laden fluid by passing the particle-laden fluidover an undulating separator body having one or more separator openingsthat extends over at least one bleed hole through the first wall. Thefirst portion of the particle-laden fluid is filtered by the firstportion of the particle-laden fluid bending around an edge of theseparator body at the one or more separator openings and flowing into anauxiliary fluid passageway. A second portion of the fluid passes overthe separator body without being filtered by the separator body. Themethod also includes directing the first portion of the fluid that isfiltered to one or more downstream components of the machine.

In one embodiment, a particle separator is provided. The particleseparator includes a separator body configured to be disposed in aprimary fluid passageway of a turbomachine that directs aparticle-carrying fluid along a flow path in the primary fluidpassageway toward a combustor of the turbomachine. The primary fluidpassageway of the turbomachine is located between an inner wall and anouter wall that is disposed radially outside of the inner wall from acenterline of the turbomachine. A rotor assembly of the turbomachinerotates around the centerline of the turbomachine. The primary fluidpassageway includes one or more air bleed holes through which a divertedportion of the fluid flowing in the primary fluid passageway toward thecombustor is diverted into an auxiliary flow passageway that bypassesthe combustor and directs the diverted portion of the fluid toward oneor more components of the turbomachine that are downstream of thecombustor in the turbomachine. The separator body extends along the flowpath from an upstream end that is configured to be coupled with theinner wall of the primary fluid passageway. The separator body includesat least one upstream edge positioned to separate at least someparticles carried by the fluid from the fluid as the diverted portion ofthe fluid bends around and flows over the at least one upstream edge ofthe separator body and into the auxiliary flow passageway via the one ormore cooing air bleed holes while a non-diverted portion of the fluidcontinues to flow along the flow path in the primary fluid passageway.

In one embodiment, a method includes establishing a fluid flow ofparticle-laden air in a primary fluid passageway of a turbomachine thatis defined by an inner wall and a radially outward wall relative to acenterline of the turbomachine, filtering a first portion of theparticle-laden air by passing the particle-laden air over an undulatingseparator body having one or more separator openings, that is coupledwith the inner wall of the primary fluid passageway, and that extendsover at least one air bleed hole through the inner wall. The firstportion of the particle-laden air is filtered by the first portion ofthe particle-laden air bending around an edge of the separator body atthe one or more separator openings and flowing into an auxiliary fluidpassageway. A second portion of the air passes over the separator bodywithout being filtered by the separator body. The method also includesdirecting the first portion of the air that is filtered around acombustor of the turbomachine to one or more downstream components ofthe turbomachine while the second portion of the air is directed intothe combustor of the turbomachine.

In one embodiment, a turbomachine includes a compressor sectionconfigured to receive particle-laden air and to at least partiallycompress the particle-laden air and a primary fluid passageway fluidlycoupled with the compressor section and including opposing inner andradially outward walls. The primary fluid passageway is configured toreceive the particle-laden air that is compressed by the compressorsection. The primary fluid passageway includes one or more air bleedholes in one or more of the inner wall or the outer wall that arefluidly coupled with an auxiliary flow passageway. The turbomachine alsoincludes a combustor section fluidly coupled with the compressor sectionby the primary fluid passageway. The combustor section is configured tocombust an unfiltered portion of the particle-laden air and formcombustion gases. The turbomachine also includes a turbine sectionfluidly coupled with the combustor section and configured to receive thecombustion gases from the combustor section. The turbine sectionincludes turbine stages configured to be coupled with a rotor sectionand that are configured to be rotated by the combustion gases to rotatethe rotor section. The turbine section also is fluidly coupled with theauxiliary flow passageway. The turbomachine also includes a separatorbody configured to be disposed in the primary fluid passagewaydownstream of the compressor section and upstream of the combustorsection along a flow path of the particle-laden air. The separator bodyincludes at least one upstream edge positioned to separate at least someparticles carried from the particle-laden air as a diverted portion ofthe particle-laden air bends around and flows over the at least oneupstream edge of the separator body and into the auxiliary flowpassageway via the one or more cooing air bleed holes while anon-diverted portion of the particle-laden air continues to flow overthe separator body and along the flow path in the primary fluidpassageway to the combustor section. The auxiliary flow passagewaybypasses the combustor section and directs the diverted portion of thefluid toward the turbine stages via the auxiliary flow passageway.

In one embodiment, a particle separator for a turbomachine is provided.The turbomachine includes a first wall and a second wall at leastpartially defining at least one primary fluid passage. The first wallfurther defines at least one auxiliary fluid passage. The particleseparator includes a first portion including a first end and a secondend opposite the first end. The first end is coupled to the first wall.The second end extends from the first wall into the at least one primaryfluid passage and extends in a direction at least partially defined by adirection of fluid flow through the at least one primary fluid passage.The second end and the first wall at least partially define at least onefluid diversion passage coupled in flow communication with the at leastone primary fluid passage and the at least one auxiliary fluid passage.The at least one fluid diversion passage is configured to divert fluidfrom the at least one primary fluid passage to the at least oneauxiliary fluid passage in a direction at least partially opposed to thedirection of fluid flow through the at least one primary fluid passage.

In one embodiment, a turbomachine is provided. The turbomachine includesa compressor, a turbine rotatably coupled to the compressor, and acombustor coupled in flow communication with the compressor and theturbine. The turbomachine further includes a combustor bypass systemincluding a first wall and a second wall at least partially defining atleast one primary fluid passage. The first wall further defines at leastone auxiliary fluid passage. The turbomachine further includes aparticle separator including a first portion. The first portion includesa first end and a second end opposite the first end. The first end iscoupled to the first wall. The second end extends from the first wallinto the at least one primary fluid passage and extends in a directionat least partially defined by a direction of fluid flow through the atleast one primary fluid passage. The second end and the first wall atleast partially define at least one fluid diversion passage coupled inflow communication with the at least one primary fluid passage and theat least one auxiliary fluid passage. The at least one fluid diversionpassage is configured to divert fluid from the at least one primaryfluid passage to the at least one auxiliary fluid passage in a directionthat is at least partially opposed to the direction of fluid flowthrough the at least one primary fluid passage.

In one embodiment, a method of enhancing particle removal from a fluidflow in a turbomachine is provided. The turbomachine includes a firstwall and a second wall at least partially defining at least one primaryfluid passage. The first wall further defines at least one auxiliaryfluid passage. The turbomachine further includes a particle separatorincluding a first portion. The first portion includes a first end and asecond end opposite the first end. The first end is coupled to the firstwall. The second end extends from the first wall into the at least oneprimary fluid passage and extends in a direction at least partiallydefined by a direction of fluid flow through the at least one primaryfluid passage. The second end and the first wall at least partiallydefine at least one fluid diversion passage. The method includesinducing a fluid flow in the turbomachine. The method also includesestablishing primary fluid flow through the at least one primary fluidpassage. The method further includes establishing auxiliary fluid flowthrough the at least one auxiliary fluid passage including diverting atleast a portion of the primary fluid flow through the at least one fluiddiversion passage. The at least one fluid diversion passage divertsfluid flow from the at least one primary fluid passage to the at leastone auxiliary fluid passage in a direction that is at least partiallyopposed to the direction of fluid flow through the at least one primaryfluid passage

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the presentdisclosure will become better understood when the following detaileddescription is read with reference to the accompanying drawings in whichlike characters represent like parts throughout the drawings, wherein:

FIG. 1 is a schematic diagram of an exemplary turbomachine, i.e., aturbine engine;

FIG. 2 is a schematic view of an exemplary particle separator that maybe used with the turbine engine shown in FIG. 1;

FIG. 3 is a perspective view of the particle separator shown in FIG. 2;

FIG. 4 is a flow characteristic diagram of the particle separator shownin FIG. 2;

FIG. 5 is a separation graph for the particle separator shown in FIG. 2;

FIG. 6 is a schematic view of an alternative particle separator that maybe used with the turbine engine shown in FIG. 1;

FIG. 7 is a perspective view of the particle separator shown in FIG. 6;

FIG. 8 is a flow characteristic diagram of the particle separator shownin FIG. 6;

FIG. 9 is a separation graph for the particle separator shown in FIG. 6;

FIG. 10 is a schematic view of another alternative particle separatorthat may be used with the turbine engine shown in FIG. 1; and

FIG. 11 is a flow diagram for an exemplary method of enhancing particleremoval from a fluid flow in the turbine engine shown in FIG. 1.

FIG. 12 is a schematic view of an alternative particle separator thatmay be used with the turbine engine shown in FIG. 1.

FIG. 13 is a schematic view of an alternative particle separator thatmay be used with the turbine engine shown in FIG. 1.

Unless otherwise indicated, the drawings provided herein are meant toillustrate features of embodiments of this disclosure. These featuresare believed to be applicable in a wide variety of systems comprisingone or more embodiments of this disclosure. As such, the drawings arenot meant to include all conventional features known by those ofordinary skill in the art to be required for the practice of theembodiments disclosed herein.

DETAILED DESCRIPTION

In the following specification and the claims, reference will be made toa number of terms, which shall be defined to have the followingmeanings. The singular forms “a”, “an”, and “the” include pluralreferences unless the context clearly dictates otherwise. “Optional” or“optionally” means that the subsequently described event or circumstancemay or may not occur, and that the description includes instances wherethe event occurs and instances where it does not. Approximatinglanguage, as used herein throughout the specification and claims, may beapplied to modify any quantitative representation that could permissiblyvary without resulting in a change in the basic function to which it isrelated. Accordingly, a value modified by a term or terms, such as“about”, “approximately”, and “substantially”, are not to be limited tothe precise value specified. In at least some instances, theapproximating language may correspond to the precision of an instrumentfor measuring the value. Here and throughout the specification andclaims, range limitations may be combined and/or interchanged, suchranges are identified and include all the sub-ranges contained thereinunless context or language indicates otherwise.

Particle separating devices described herein provide a cost-effectivemethod for reducing sand particles and/or particulate matter within theflow of fluids within turbomachines. For example, the devices describedherein can be used to filter particulates from the flow of air incooling systems of turbomachines, from the flow of purge air directed toseals of turbomachines, to filter other fluids outside of turbomachines,etc. While the description herein may focus on use of separating devicesfor filtering cooling air in turbomachines, not all embodiments are solimited. One or more embodiments of the inventive subject matterdescribed herein can be used to filter particulates from other fluidsand/or for systems other than cooling systems of turbomachines.Specifically, to reduce particles within the flow of a fluid, theparticle separators described herein utilize the difference in inertiabetween particles and fluid molecules as a separation mechanism. Theparticle separator is located over a extraction hole serving as aparticle shield such that particles are restricted from directlyentering the cooling passage. Additionally, the particle separatormodifies a cross-sectional area of a flow passage, acceleratingparticle-laden flow therein. A fluid is routed through a fluid diversionpassage within the particle separator. Particle-laden fluid flow has toturn approximately 180° at the fluid diversion passage such thatparticles with higher inertia are separated and carried downstream. Assuch, the amount of particles traveling into the diversion passage issubstantially decreased. The particle separators described herein offeradvantages that include, without limitation, cost effectiveimplementation and retro fit application. Additionally, the particleseparators described herein, have a lower weight than many knownparticle separators, thereby reducing any weight penalties in anaircraft engine retrofit. Moreover, use of the particle separatorsdescribe herein maintain the effectiveness of cooling systems withinturbomachines by reducing particle accumulation around small featuressuch as rims, film cooling holes, and turbulators, which extends enginecomponent service life, and reduces engine downtime and maintenancecosts.

As used herein, the terms “axial” and “axially” refer to directions andorientations which extend substantially parallel to a centerline 126, asshown in FIG. 1, of a turbine engine. Moreover, the terms “radial” and“radially” refer to directions and orientations which extendsubstantially perpendicular to the centerline of the turbine engine. Inaddition, as used herein, the terms “circumferential” and“circumferentially” refer to directions and orientations which extendarcuately about the centerline of the turbine engine. The term “fluid,”as used herein, includes any medium or material that flows, including,but not limited to air.

FIG. 1 is a schematic view of a rotary machine 100, i.e., aturbomachine, and more specifically, a turbine engine. In the exemplaryembodiment, turbine engine 100 is an aircraft engine. Alternatively,turbine engine 100 is any other turbine engine and/or rotary machine,including, without limitation, a gas turbine engine. In the exemplaryembodiment, turbine engine 100 includes an air intake section 102, and acompressor section 104 that is coupled downstream from, and in flowcommunication with, intake section 102. Compressor section 104 isenclosed within a compressor casing 105. A combustor section 106 iscoupled downstream from, and in flow communication with, compressorsection 104, and a turbine section 108 is coupled downstream from, andin flow communication with, combustor section 106. Turbine engine 100 isenclosed within a turbine casing 109 and includes an exhaust section 110that is downstream from turbine section 108. A combustor housing 111extends about combustor section 106 and is coupled to compressor casing105 and turbine casing 109. Moreover, in the exemplary embodiment,turbine section 108 is coupled to compressor section 104 via a rotorassembly 112 that includes, without limitation, a compressor rotor, ordrive shaft 114 and a turbine rotor, or drive shaft 115.

In the exemplary embodiment, combustor section 106 includes a pluralityof combustor assemblies, i.e., combustors 116 that are each coupled inflow communication with compressor section 104. Combustor section 106also includes at least one fuel nozzle assembly 118. Each combustor 116is in flow communication with at least one fuel nozzle assembly 118.Moreover, in the exemplary embodiment, turbine section 108 andcompressor section 104 are rotatably coupled to a fan assembly 120 viadrive shaft 114. Alternatively, aircraft engine 100 may be a gas turbineengine and for example, and without limitation, be rotatably coupled toan electrical generator and/or a mechanical drive application, e.g., apump. In the exemplary embodiment, compressor section 104 includes atleast one compressor blade assembly 122, i.e., blade 122 and at leastone adjacent stationary vane assembly 123.

Also, in the exemplary embodiment, turbine section 108 includes at leastone turbine blade assembly, i.e., blade 125 and at least one adjacentstationary nozzle assembly 124. Each compressor blade assembly 122 andeach turbine blade 125 is coupled to rotor assembly 112, or, morespecifically, compressor drive shaft 114 and turbine drive shaft 115.

In operation, an intake section 102 channels a fluid 150 (such as butnot limited to air) toward compressor section 104. Compressor section104 compresses inlet fluid 150 to higher pressures and temperaturesprior to discharging compressed fluid 152 towards combustor section 106.Compressed air 152 is channeled to fuel nozzle assembly 118, mixed withfuel (not shown), and burned within each combustor 116 to generatecombustion gases 154 that are channeled downstream towards turbinesection 108. After impinging turbine blade 125, thermal energy isconverted to mechanical rotational energy that is used to drive rotorassembly 112. Turbine section 108 drives compressor section 104 and/orfan assembly 120 via drive shafts 114 and 115, and exhaust gases 156 aredischarged through exhaust section 110 to ambient atmosphere.

FIG. 2 is a schematic view of an exemplary particle separator 200 thatmay be used with turbine engine 100. In the exemplary embodiment,turbine engine 100 includes a handling system 202 that channels a fluidtoward one or more components such as blade 125 (shown in FIG. 1). Forexample, the handling system 202 may direct cooling air toward one ormore air-cooled components, such as one or more turbine blades 125. Thehandling system 202 includes at least one primary fluid passage 204,such as a combustor bypass passage, coupled in flow communication withat least one auxiliary fluid passage 206, such as a cooling air passage.Compressed fluid 152 discharged from compressor section 104 (shown inFIG. 1) is split into a combustion flow 208 channeled towards combustorsection 106 (shown in FIG. 1) and a combustor bypass flow 210 channeledaround combustor section 106 (shown in FIG. 1) within primary fluidpassage 204.

Combustor bypass flow 210 includes a primary fluid flow 216 throughprimary fluid passage 204 and an auxiliary fluid flow 218 throughauxiliary fluid passage 206. Primary fluid flow 216 flows throughprimary fluid passage 204 that is defined by a second wall 212 and afirst wall 214. First wall 214 further defines auxiliary fluid passage206. Auxiliary fluid flow 218 flows through auxiliary fluid passage 206towards the air-cooled component.

In the exemplary embodiment, particle separator 200 includes a firstportion 220. First portion 220 has a first end 222 and a second end 224opposite first end 222. First end 222 of first portion 220 is coupled tofirst wall 214. Second end 224 of first portion 220 extends radiallyfrom first wall 214 into primary fluid passage 204 and extends axiallyfrom first end 222 of first portion 220 in a direction defined byprimary fluid flow 216 through primary fluid passage 204. Second end 224of first portion 220 and first wall 214 define at least one fluiddiversion passage 228. Fluid diversion passage 228 is coupled in flowcommunication with primary fluid passage 204 and auxiliary fluid passage206. Fluid diversion passage 228 diverts fluid from primary fluidpassage 204 to auxiliary fluid passage 206 in a direction that isopposed to primary fluid flow 216 through primary fluid passage 204.

Furthermore, in the exemplary embodiment, particle separator 200includes a flow member 230 disposed within primary fluid passage 204between second wall 212 and first portion 220. Flow member 230 extendsaxially in a direction defined by primary fluid flow 216 through primaryfluid passage 204. Additionally, flow member 230 is disposed withinprimary fluid passage 204 at a radial distance from first wall 214within a range from greater than or equal to 20 percent of primary fluidpassage radial height to less than or equal to 90 percent of primaryfluid passage radial height. Flow member 230 is configured to straightenand/or divide primary fluid flow 216. By creating a more uniform primaryfluid flow 216, particle separation efficiency increases at particleseparator 200. Flow member 230 is coupled to at least one of first wall214, second wall 212, and first portion 220. In the exemplaryembodiment, flow member 230 has a curvature that is substantiallysimilar to the curvature of second wall 212. In alternative embodiments,flow member 230 may have any other shape that allows particle separator200 to operate as described herein. In other alternative embodiments,particle separator 200 does not include flow member 230.

FIG. 3 is a perspective view of particle separator 200 that may be usedwith turbine engine 100. As described above, particle separator 200 iscoupled to first wall 214 at first end 222 of first portion 220.Particle separator 200 further includes a support device 232 including acoupling member 234 and a plurality of support members 236. Supportmembers 236 are coupled to coupling member 234 and extend radially fromfirst wall 214 into primary fluid passage 204. Coupling member 234 iscoupled to first wall 214 and support members 236 are coupled to secondend 224 of first portion 220.

In the exemplary embodiment, first portion 220 and support device 232are unitary. In some alternative embodiments, first portion 220, flowmember 230, and support device 232 are unitary. In some otheralternative embodiments, first portion 220, support device 232, and flowmember 230 are separate members that are coupled together. As shown inFIG. 3, particle separator 200 spans substantially circumferentiallyacross primary fluid passage 204 and extends over inlet hole 226. Insome alternative embodiments, particle separator 200 is a discretemember that extends over inlet hole 226 only and does not spancircumferentially across primary fluid passage 204. Additionally,particle separator 200 is made from sheet metal or any other suitablematerial.

FIG. 4 is a flow characteristic diagram 250 of the particle separator200 as described above. Flow characteristic diagram 250 shows particletrajectories within cooling system 202. Particle-laden primary fluidflow 216 is channeled through primary fluid passage 204. First portion220 of particle separator 200 extends over inlet hole 226 which reducesdirect particle entry into auxiliary fluid passage 206 fromparticle-laden primary fluid flow 216.

Particle entry into auxiliary fluid passage 206 is also reduced by fluidproperties created by particle separator 200. Particles are separatedwithin the flow by the difference in inertia between particles and airmolecules. First portion 220 has a ramp-like shape that acceleratesparticle-laden primary fluid flow 216 in an axial direction by reducingthe cross-sectional area of primary fluid passage 204. In the exemplaryembodiment, fluid flow is accelerated to approximately a Mach number of0.1 or higher. Although, it is appreciated that any acceleration thatincreases inertia of particles will reduce particles in auxiliary fluidpassage 206.

When primary fluid flow 216 is accelerated, the particles have a greateramount of inertia than the fluid molecules. Auxiliary fluid flow 218,which can be used for cooling or other purposes, is diverted fromprimary fluid flow 216 through fluid diversion passage 228. Thisdiversion forces auxiliary fluid flow 218 to turn approximately 180°around second end 224 of first portion 220 before entering auxiliaryfluid passage 206. The particles having high inertia are removed throughcentrifugal force and carried further downstream with primary fluid flow216. The clear area in FIG. 4 around fluid diversion passage 228 showsthat particle entry into auxiliary fluid passage 206 is reduced andauxiliary fluid flow 218, which makes the turn at fluid diversionpassage 228, contains fewer particles as shown in FIG. 5, discussedbelow.

FIG. 5 is a separation graph 260 that includes a y-axis 262 definingefficiency of particle separation from auxiliary fluid flow 218. Graph260 also includes an x-axis 264 defining particle size. Graph 260 showstwo efficiency of particle separation versus particle size curves forauxiliary fluid flow. The uppermost curve 266 is the curve for auxiliaryfluid flow 218 with particle separator 200 extending over cooling inlethole 226. The lowermost curve 268 is the curve for auxiliary fluid flow218 without particle separator 200 extending over inlet hole 226. Thehigher the efficiency of particle separation, the cleaner the fluid.

FIG. 6 is a schematic view of an alternative particle separator 300 thatmay be used with turbine engine 100. In this alternative embodiment,turbine engine 100 includes a handling system 202 that channels fluidtoward another component as described above in reference to FIG. 2. Asone example, the handling system 202 may be a cooling system thatchannels cooling air toward one or more air-cooled components. In thisalternative embodiment, particle separator 300 includes a first portion302, a second portion 308, and at least one third portion 314. Firstportion 302 has a first end 304 and a second end 306 opposite first end304. First end 304 of first portion 302 is coupled to first wall 214.Second end 306 of first portion 302 extends radially from first wall 214into primary fluid passage 204 and extends axially from first end 304 offirst portion 302 in a direction defined by primary fluid flow 216through primary fluid passage 204. Second portion 308 also has a firstend 310 and a second end 312 opposite first end 310. First end 310 ofsecond portion 308 extends radially from first wall 214 into primaryfluid passage 204. First end 310 of second portion 308 extends axiallyin a direction opposed to primary fluid flow 216 through primary fluidpassage 204. Second end 312 of second portion 308 is coupled to firstwall 214. In some alternative embodiments, second portion 308 extends ina direction substantially normal to primary fluid flow 216 throughprimary fluid passage 204. In some other alternative embodiments, secondportion 308 extends in a direction substantially aligned to primaryfluid flow 216 through primary fluid passage 204.

In this alternative embodiment, particle separator 300 includes thirdportion 314 between first portion 302 and second portion 308. Thirdportion 314 has a first end 316 and a second end 318 opposite first end316. Third portion 314 extends axially in a direction defined by primaryfluid flow 216 through primary fluid passage 204. At least one firstfluid diversion passage 320 is defined by second end 306 of firstportion 302 and first end 316 of third portion 314. At least one secondfluid diversion passage 322 is defined by second end 318 of thirdportion 314 and first end 310 of second portion 308. First and secondfluid diversion passages 320, 322 are coupled in flow communication withprimary fluid passage 204 and auxiliary fluid passage 206. First andsecond fluid diversion passages 320, 322 divert fluid from primary fluidpassage 204 to auxiliary fluid passage 206 in a direction that isopposed to primary fluid flow 216 through primary fluid passage 204.

Also, in this alternative embodiment, first portion 302, second portion308, and third portion 314 are shown as substantially “S” shaped. Forexample, first end 316 of third portion 314 has a local curvature radius(first curve in the “S”) greater than or equal to 10 percent of thirdportion 314 axial length, and second end 318 of third portion 314 has alocal curvature radius (second curve in the “S”) greater than or equalto 20 percent of third portion 314 axial length. Moreover, for example,second end 318 of third portion 314 has a flap angle (end angle curvedeither towards first wall 214 or second wall 212) within a range fromless than or equal to 10 degrees into second wall 212 (such that endangle curves toward second wall 212) to less than or equal to 60 degreesinto first wall 214 (such that end angle curves towards first wall 214).The flap angle also has a local curvature radius of greater than orequal to 50 percent of second gap height 332 (discussed further below).Furthermore, for example, second end 318 of third portion 314 and firstend 310 of second portion 308 are spaced from one another within a rangefrom axially overlapping one another at a distance of approximatelytwice the second gap height 332 to having an axial gap between oneanother with a distance of approximately twice the second gap height332. Also, for example, the angle between second end 318 of thirdportion 314 and first end 310 of second portion 308 is within a rangefrom greater than or equal to 0 degrees (such that second end 318 ofthird portion 314 and first end 310 of second portion 308 are parallel)to less than or equal to 60 degrees. Alternatively, first portion 302,second portion 308, and third portion 314 are other shapes, including,but not limited to, flat, “L” shaped, and “C” shaped.

Furthermore, in this alternate embodiment, particle separator 300includes a flow member 334 disposed within primary fluid passage 204between second wall 212 and first portion 302, second portion 308, andthird portion 314. Flow member 334 extends axially in a directiondefined by primary fluid flow 216 through primary fluid passage 204.Additionally, flow member 334 is disposed within primary fluid passage204 at a radial distance from first wall 214 within a range from greaterthan or equal to 20 percent of primary fluid passage radial height toless than or equal to 90 percent of primary fluid passage radial height.Flow member 334 is configured to straighten and/or divide primary fluidflow 216. By creating a more uniform primary fluid flow 216, particleseparation efficiency increases at particle separator 300. Flow member334 is attached to at least one of first wall 214, second wall 212,first portion 302, second portion 308, and third portion 314. In theexemplary embodiment, flow member 334 has a curvature that issubstantially similar to the curvature of second wall 212. Inalternative embodiments, flow member 334 may have any other shape thatallows particle separator 300 to operate as described herein. In otheralternative embodiments, particle separator 300 does not include flowmember 334.

FIG. 7 is a perspective view of particle separator 300 that may be usedwith turbine engine 100. As described above, particle separator 300 iscoupled to first wall 214 at first end 304 of first portion 302 andsecond end 312 of second portion 308. In this alternative embodiment,first portion 302, second portion 308, and third portion 314 areunitary. In some alternative embodiments, first portion 302, secondportion 308, and third portion 314 are separate members that are coupledtogether. As shown in FIG. 7, particle separator 300 spans substantiallycircumferentially across primary fluid passage 204 and extends overinlet hole 226. In some alternative embodiments, particle separator 300is a discrete member that extends over cooling inlet hole 226 only anddoes not span circumferentially across primary fluid passage 204.

FIG. 8 is a flow characteristics diagram 350 of particle separator 300as described above. Flow characteristic diagram 350 shows particletrajectories within cooling system 202. Particle-laden primary fluidflow 216 is channeled through primary fluid passage 204. Particleseparator 300 extends over inlet hole 226 which reduces direct particleentry into auxiliary fluid passage 206 from particle-laden primary fluidflow 216.

Particle entry into auxiliary fluid passage 206 is also reduced by fluidproperties created by particle separator 300, similar to the fluidproperties discussed above in reference to FIG. 4. First portion 302 andthird portion 314 create a ramp-like shape that acceleratesparticle-laden primary fluid flow 216 in an axial direction by reducingthe cross-sectional area of primary fluid passage 204. Additionally,second portion 308 further improves particle separation effectiveness bypromoting attached continuous flow. In this alternative embodiment,second portion 308 has a convex fairing downstream. In some alternativeembodiments, second portion 308 is any suitable shape that enablesoperation of particle separator 300 as described herein.

Auxiliary fluid flow 218, which can be used for cooling, for a purge airin a turbomachinery seal between a rotor and a stator, or the like, isdiverted from primary fluid flow 216 through first and second fluiddiversion passages 320, 322. This diversion forces auxiliary fluid flow218 to turn approximately 180° around second end 306 of first portion302 and second end 318 of third portion 314 before entering auxiliaryfluid passage 206. The clear area in FIG. 8 around first and secondfluid diversion passages 320, 322 shows that particle entry intoauxiliary fluid passage 206 is reduced and auxiliary fluid flow 218,which makes the turns at first and second fluid diversion passages 320,322, contains fewer particles as shown in FIG. 9, discussed below.

In this alternative embodiment, the fluid passage height affects theamount of flow acceleration through primary fluid passage 204. A firstprimary fluid passage height 326 defined by second end 306 of firstportion 302 and second wall 212. A second primary fluid passage height328 is defined by second end 318 of third portion 314 and second wall212. In this alternative embodiment, second primary fluid passage height328 is less than first primary fluid passage height 326. First andsecond primary fluid passage heights 326 and 328 have a height within arange from greater than or equal to 10 percent of primary fluid passageradial height to less than or equal to 90 percent of primary fluidpassage radial height. In some alternative embodiments, first and secondprimary fluid passage heights 326, 328 are equal height to one another.

In this alternative embodiment, the fluid diversion passage heightaffects the particle separation at first and second fluid diversionpassages 320, 322. First fluid diversion passage 320 has a first gapheight 330 defined by second end 306 of first portion 302 and first end316 of third portion 314. Second fluid diversion passage 322 has asecond gap height 332 defined by second end 318 of third portion 314 andfirst end 310 of second portion 308. In this alternative embodiment,first gap height 330 is substantially equal to second gap height 332. Insome alternative embodiments, first and second gap heights 330, 332 aredifferent from one another.

FIG. 9 is a separation graph 360 that includes a y-axis 362 definingefficiency of particle separation from auxiliary fluid flow 218. Graph360 also includes an x-axis 364 defining a particle size. Graph 360shows three efficiency of particle separation versus particle sizecurves for auxiliary fluid flow 218. The uppermost curve 366 is thecurve for auxiliary fluid flow 218 with particle separator 300. Themiddle curve 368 is the curve for auxiliary fluid flow 218 with particleseparator 200 as described above in reference to FIGS. 2-5. Thelowermost curve 370 is the curve for auxiliary fluid flow 218 withoutparticle separator 300. The higher the efficiency of particleseparation, the cleaner the fluid is (e.g., the cleaner that the coolingair, purge air, or other liquid for the air cooled component or foranother use).

FIG. 10 is a schematic view of another alternative particle separator400 that may be used with turbine engine 100. In this alternativeembodiment, turbine engine 100 includes a handling system 202 thatchannels fluid toward another component as described above in referenceto FIG. 2. Additionally, in this alternative embodiment, particleseparator 400 includes a first portion 302, a second portion 308, and atleast one third portion 314 as described above in reference to FIG. 6.

In this alternative embodiment, at least one third portion 314 furtherincludes a first section 402, a second section 408, and third section414. First section 402, second section 408, and third section 414 arebetween first portion 302 and second portion 308 as shown in FIG. 10.First section 402 has a first end 404 and a second end 406 opposite offirst end 404. Second section 408 has a first end 410 and second end 412opposite of first end 410. Third section 414 has a first end 416 andsecond end 418 opposite of first end 416. First section 402, secondsection 408, and third section 414 all extend axially in a directiondefined by primary fluid flow 216 through primary fluid passage 204.

Also, in this alternative embodiment, first section 402, second section408, and third section 414 are shown as substantially “S” shaped. Forexample, first end 404 of first section 402 has a local curvature radius(first curve in the “5”) greater than or equal to 10 percent of firstsection 402 axial length, and second end 406 of first section 402 has alocal curvature radius (second curve in the “S”) greater than or equalto 20 percent of first section 402 axial length. Moreover, for example,second end 406 of first section 402 has a flap angle (end angle curvedeither towards first wall 214 or second wall 212) within a range fromless than or equal to 10 degrees into second wall 212 (such that endangle curves toward second wall 212) to less than or equal to 60 degreesinto first wall 214 (such that end angle curves towards first wall 214).The flap angle also has a local curvature radius of greater than orequal to 50 percent of third gap height 440 (discussed further below).Furthermore, for example, second end 406 of first section 402 and firstend 410 of second section 408 are spaced from one another within a rangefrom axially overlapping one another at a distance of approximatelytwice the third gap height 440 to having an axial gap between oneanother with a distance of approximately twice the third gap height 440.Also, for example, the angle between second end 406 of first section 402and first end 410 of second section 408 is within a range from greaterthan or equal to 0 degrees (such that second end 406 of first section402 and first end 410 of second section 408 are parallel) to less thanor equal to 60 degrees. Alternatively, first section 402, second section408, and third section 414 are other shapes, including, but not limitedto, flat, “L” shaped, and “C” shaped. Additionally, in this alternativeembodiment at least one third portion 314 is shown with three sections402, 408, 414. In some alternative embodiments, at least one thirdportion 314 includes, but not limited to, two, five, and six sections.

Further, in this alternate embodiment, particle separator 400 includes aflow member 444 disposed within primary fluid passage 204 between secondwall 212 and first portion 302, second portion 308, and at least onethird portion 314. Flow member 444 extends axially in a directiondefined by primary fluid flow 216 through primary fluid passage 204.Additionally, flow member 444 is disposed within primary fluid passage204 at a radial distance from first wall 214 within a range from greaterthan or equal to 20 percent of primary fluid passage radial height toless than or equal to 90 percent of primary fluid passage radial height.Flow member 444 is configured to straighten and/or divide primary fluidflow 216. By creating a more uniform primary fluid flow 216, particleseparation efficiency increases at particle separator 400. Flow member444 is attached to at least one of first wall 214, second wall 212,first portion 302, second portion 308, and at least one third portion314. In the exemplary embodiment, flow member 444 has a curvature thatis substantially similar to the curvature of second wall 212. Inalternative embodiments, flow member 444 may have any other shape thatallows particle separator 400 to operate as described herein. In otheralternative embodiments, particle separator 400 does not include flowmember 444.

Additionally, in this alternative embodiment, first section 402, secondsection 408, and third section 414 are unitarily coupled to firstportion 302 and second portion 308. In some alternative embodiments,first section 402, second section 408, and third section 414 areunitary. In yet some other alternative embodiments, first section 402,second section 408, and third section 414 are separate members that arecoupled together. Particle separator 400 spans substantiallycircumferentially across primary fluid passage 204 and extending overcooling inlet hole 226. In some alternative embodiments, particleseparator 400 is a discrete member that extending over cooling inlethole 226 only and does not span circumferentially across primary fluidpassage 204.

Moreover, in this alternative embodiment, at least one first fluiddiversion passage 420 is defined by second end 306 of first portion 302and first end 404 of first section 402. At least one second fluiddiversion passage 422 is defined by second end 418 of third section 414and first end 310 of second portion 308. At least one third fluiddiversion passage 424 is defined by second end 406 of first section 402and first end 410 of second section 408. At least one fourth fluiddiversion passage 426 is defined by second end 412 of second section 408and first end 416 of third section 414. First, second, third, and fourthfluid diversion passages 420, 422, 424, 426 are coupled in flowcommunication with primary fluid passage 204 and auxiliary fluid passage206. First, second, third, and fourth fluid diversion passages 420, 422,424, 426 divert fluid from primary fluid passage 204 to auxiliary fluidpassage 206 in a direction that is opposed to primary fluid flow 216through primary fluid passage 204.

In addition, in this alternative embodiment, a first primary fluidpassage height 428 is defined by second end 306 of first portion 302 andsecond wall 212. A second primary fluid passage height 430 is defined bysecond end 406 of first section 402. A third primary fluid passageheight 432 is defined by second end 412 of second section 408. A fourthprimary fluid passage height 434 is defined by second end 418 of thirdsection 414. In this alternative embodiment, second primary fluidpassage height 430 is less than first primary fluid passage height 428,third primary fluid passage height 432 is less than second primary fluidpassage height 430, and fourth primary fluid passage height 434 is lessthan third primary fluid passage height 432. First, second, third, andfourth primary fluid passage heights 428, 430, 432, and 434 have aheight within a range from greater than or equal to 10 percent ofprimary fluid passage radial height to less than or equal to 90 percentof primary fluid passage height. In some alternative embodiments, first,second, third, and fourth fluid passage heights 428, 430, 432, 434 areof equal height to one another. Similar to particle separator 300described above in reference to FIGS. 6-9, particle separator 400accelerates particle-laden primary fluid flow 216 in an axial directionby reducing the cross-section area of primary fluid passage 204.

Also, in this alternative embodiment, first fluid diversion passage 420has a first gap height 436 defined by second end 306 of first portion302 and first end 404 of first section 402. Second fluid diversionpassage 422 has a second gap height 438 defined by second end 418 ofthird section 414 and first end 310 of second portion 308. Third fluiddiversion passage 424 has a third gap height 440 defined by second end406 of first section 402 and first end 410 of second section 408. Fourthfluid diversion passage 426 has a fourth gap height 442 defined bysecond end 412 of second section 408 and first end 416 of third section414. In this alternative embodiment, first gap height 436 issubstantially equal to second gap height 438. First gap height 436 isalso substantially equal to third gap height 440 and fourth gap height442. In some alternative embodiments, first, second, third, and fourthgap heights 436, 438, 440, 442 are different from one another.

Similar to particle separator 300 described above in reference to FIGS.6-9, particle-laden auxiliary fluid flow 218 turns approximately 180°about first, second, third, and fourth fluid diversion passages 420,422, 424, 426 before entering into auxiliary fluid passage 206. Theturns at first, second, third, and fourth fluid diversion passages 420,422, 424, 426 separates heavier particles from auxiliary fluid flow 218.The heavier particles stay within primary fluid flow 216 and continuethrough primary fluid passage 204.

FIG. 12 is a schematic view of an alternative particle separator 1200that may be used with the turbine engine 100 shown in FIG. 1.Alternatively, the particle separator 1200 can be used with anothersystem. The particle separator 1200 includes a separator body 1202 thatcan be disposed in the primary fluid passageway 204 described above. Asingle cooling air bleed hole 1204 extends through the first wall 214(also referred to as the radially inner or inward wall of the primaryfluid passageway 204) to fluidly couple the primary fluid passageway 204with the auxiliary fluid passageway 206 described above. Optionally, theinner wall 214 may include more than a single bleed hole 1204.

The separator body 1202 extends along a flow path or direction 1212 inwhich particle-laden fluid 1222 (“Dust-laden air” in FIG. 12, but notall embodiments are limited to air) flows in the primary fluidpassageway 204 from an upstream end 1206 to an opposite downstream end1216. In the illustrated embodiment, the upstream end 1206 of theseparator body 1202 is upstream of the bleed hole 1204 and thedownstream end 1216 of the separator body 1202 is downstream of thebleed hole 1204 along the flow path 1212 in the primary fluid passageway 204. Alternatively, the upstream end 1206 of the separator body 1202may be closer to the bleed hole 1204 than what is shown in FIG. 12. Theflow path 1212 radially extends along radial directions 1228 from theinner wall 214 to the outer wall 212. The flow path 1212 is elongatedalong axial directions 1230 such that the particle-laden fluid 1222flows along the flow path 1212 between the walls 212, 214. The radialdirection(s) 1228 radially extend outward from the centerline 126 of theturbomachine 100 and the axial direction(s) 1230 extend parallel to thecenterline 126 of the turbomachine 100.

In the illustrated embodiment, the upstream end 1206 of the separatorbody 1202 is coupled with or sealed to the inner wall 214 and thedownstream end 1216 of the separator body 1202 is coupled with or sealedto the inner wall 214. This coupling or sealing can enclose the bleedhole 1204 beneath the separator body 1202 along the radial direction(s)1228. The sealing or coupling of the upstream end 1206 of the separatorbody 1202 to the inner wall 214 can prevent passage of theparticle-laden fluid 1222 between the upstream end 1206 of the separatorbody 1202 and the inner wall 214. Alternatively, one or more portions(but not all) of the upstream end 1206 along a circumferential directionaround the center line of the turbomachine may be separated from orspaced apart from the inner wall 214 in one or more locations along theradial direction(s) 1228.

The separator body 1202 shown in FIG. 12 has an undulating shape alongthe axial direction(s) 1230. This undulating shape is formed by theseparator body 1202 having several crests 1208 (e.g., crests 1208A-D)and valleys 1210 (e.g., valleys 1210A-C) that are spaced apart from eachother in the axial direction 1230. The crests 1208 are the peak portionsof the separator body 1202 that radially extend farther from the innerwall 214 and/or centerline 126 of the turbomachine 100 along the radialdirections 1228 than the valleys 1210. The valleys 1210 are the portionsof the separator body 1202 that are closer to the inner wall 214 and/orcenterline 126 of the turbomachine 100 than the crests 1208 along theradial directions 1228. The separator body 1202 shown in FIG. 12includes four crests 1208 with three valleys 1210 between the crests1208. Alternatively, the separator body 1202 can include fewer or morecrests 1208 and/or valleys 1210. While the undulating shape in FIG. 12shows the crests 1208 being separated from each other by valleys 1210along the axial direction 1230, optionally, the separator body 1202 mayadditionally or alternatively have an undulating shape along thecircumferential directions. For example, crests 1208 may be separatedfrom each other by valleys 1210 along a direction extending into or outof the plane of FIG. 12 or along a path that encircles the centerline126 of the turbomachine 100.

In the illustrated embodiment, different crests 1208 protrude differentdistances into the primary fluid passageway 204 along the radialdirections 1228 from the inner wall 214. The crests 1208 located fartheralong the primary fluid passageway 204 in the axial direction 1230 canprotrude farther into the primary fluid passageway 204, farther from theinner wall 214, and/or closer to the outer wall 212 than other crests1208. For example, the crest 1208D extends farthest into the primaryfluid passageway 204 of the crests 1208A-D, farthest from the inner wall214 of the crests 1208A-D, and/or closest to the outer wall 212 of thecrests 1208A-D. The crest 1208C extends farther into the primary fluidpassageway 204 than the crests 1208A-B but not as far as the crest1208D, farther from the inner wall 214 than the crests 1208A-B but notas far as the crest 1208D, and/or closer to the outer wall 212 than thecrests 1208A-B but not as close as the crest 1208D, and so on.Alternatively, the crests 1208 located farther to the left in FIG. 12may extend farther from the inner wall 214 than other crests 1208, thecrests 1208 in the middle of the separator body 1202 may extend fartherfrom the inner wall 214 than other crests 1208, or the crests 1208 mayextend the same distance into the primary fluid passageway 204 from theinner wall 214.

Additionally in the illustrated embodiment, different valleys 1210 arelocated different distances from the inner wall 214 along the radialdirections 1228. The valleys 1210 located farther along the primaryfluid passageway 204 in the axial direction 1230 can be located fartherfrom the inner wall 214 and/or closer to the outer wall 212 than othervalleys 1210. For example, the valley 1210C can be located farthest fromthe inner wall 214 of the valleys 1210A-C and/or closest to the outerwall 212 of the valleys 1210A-C. The valley 1210B can be located fartherfrom the inner wall 214 than the valley 1210A but not as far as thevalley 1210C and/or closer to the outer wall 212 than the valley 1210Abut not as close as the valley 1210C, and so on. Alternatively, thevalleys 1210 located farther to the left in FIG. 12 may extend fartherfrom the inner wall 214 than other valleys 1210, the valleys 1210 in themiddle of the separator body 1202 may extend farther from the inner wall214 than other valleys 1210, or the valleys 1210 may extend the samedistance into the primary fluid passageway 204 from the inner wall 214.

The separator body 1202 includes several separator openings 1214.Alternatively, the separator body 1202 may have a single opening 1214 ormay include a different number of the separator openings 1214 (than whatis shown in FIG. 12). The separator openings 1214 extend through theentire thickness of the separator body 1202 such that fluid can flowthrough the separator body 1202 via or through the openings 1214. Theremainder of the separator body 1202 may be solid or otherwiseimpermeable to the fluid 1222. For example, the portions of theseparator body 1220 extending from the upstream edge 1206 to the firstseparator opening 1214 along the axial direction 1230, extending fromthe first separator opening 1214 to the next, second separator opening1214 along the axial direction 1230, extending from the second separatoropening 1214 to the next, third separator opening 1214 along the axialdirection 1230, extending from the third separator opening 1214 to thenext, fourth separator opening 1214 along the axial direction 1230, andextending from the fourth separator opening 1214 to the downstream edge1216 may be impermeable to the fluid 1222 such that the fluid 1222cannot pass through the separator body 1202 except through the separatoropening(s) 1214.

In the illustrated embodiment, each separator opening 1214 is downstreamof a different crest 1208 along the flow direction 1212. For example,each separator opening 1214 can be located downstream of one crest 1208but upstream of the next valley 1210 and the next crest 1208 along theflow direction 1212. Alternatively, multiple separator openings 1214 canbe downstream of at least one or each of the crests 1208 (and upstreamof the next or subsequent crest 1208 along the flow direction 1212 inthe primary fluid passageway 204).

Each separator opening 1214 can include an upstream edge 1218 and anopposing edge 1220. The upstream edges 1218 of the separator openings1214 are located radially outward of the corresponding opposing edge1220 for the same opening 1214 along the radial direction(s) 1228. Forexample, the upstream edge 1218 for a separator opening 1214 can befarther from the inner wall 214 than the opposing edge 1218 of the sameseparator opening 1214. The separation between the edges 1218, 1220 ofan opening 1214 along a radial direction away from the centerline 126 ofthe turbomachine 100 can be referred to a step height h, as shown inFIG. 12. In one embodiment, the step height h is made as small aspossible while still filtering at least a desired or threshold amount ofthe air 1222 (described below).

The separator openings 1214 provide access to and fluid coupling betweenthe primary fluid passageway 204 and the auxiliary fluid passageway 206.In operation, the particle-laden fluid 1222 flows in the primary fluidpassageway 204 and over the undulations formed by the crests 1208 and/orvalleys 1210. These undulations can control a primary fluid velocity ofthe fluid and re-attachment points of the fluid. For example, the crests1208 can accelerate the fluid and where different flow paths of thefluid re-combine after separating at the upstream edges 1218. Both thisacceleration and re-combination of flow paths can increase theefficiency at which particles are separated from the fluid. For example,without the undulations, fewer particles may be separated from thefluid.

As the particle-laden fluid 1222 flows over the upstream edges 1218 ofeach separator opening 1214, a portion of the fluid 1222 flows over andbends around the upstream edge 1218 of the separator opening 1214 andthen flows through the separator opening 1214 to the auxiliary fluidpassageway 206. Because the particles (e.g., sand, dust, etc.) carriedby the particle-laden fluid 1222 have significantly greater inertia thanthe air in the particle-laden fluid 1222, most or all the particles areunable to bend around the upstream edge 1218 of any separator opening1214. Therefore, the particles continue to flow along the flow direction1212 in the primary fluid passageway 204 (e.g., to the combustor of theturbomachine 100 or to another volume of the turbomachine 100).

The portion of the fluid 1222 that passes through any of the separatoropenings 1214 can be referred to as a filtered portion or divertedportion 1224 of the fluid 1222, while the remaining portion of the fluid1222 that continues to flow along the flow direction 1212 in the primaryfluid passageway 204 (and does not flow through any separator opening1214) can be referred to as an unfiltered portion or non-divertedportion 1226 of the fluid 1222. The filtered or diverted portion 1224 ofthe fluid 1222 also is labeled as “Clean air” in FIG. 12 as this portion1224 of the fluid 1222 carries fewer particles than the unfiltered ornon-diverted portion 1226 of the fluid 1222 (“Core flow” in FIG. 12).Not all embodiments of the subject matter described herein are limitedto filtering particles from air, however. The filtered or divertedportion 1224 can be directed around the combustor or combustor section106 of the turbomachine 100 and can be directed to one or more othercomponents. For example, the filtered portion 1224 of the fluid can bedirected to one or more blades 125 to cool the blades 125 with thefiltered fluid (and less or no particle-laden fluid, the filteredportion 1224 can be directed to a seal between a rotor and stator of theturbomachine 100 to prevent or reduce the introduction of particles intothe seal, etc. In one embodiment, the fluid may be separated into thefiltered and non-filtered portions in another location of theturbomachine or in another machine. The unfiltered or non-divertedportion 1226 of the fluid 1222 can be directed into the combustor orcombustor section 106 of the turbomachine 100 for combustion, or can bedirected to another location for another purpose.

The undulations formed by the crests 1208 and valleys 1210 of theseparator body 1202 provide the undulating shape of the separator body1202 along the axial direction 1230 of the turbomachine 100. Forexample, the crests 1208 are separated from each other along a directionthat extend parallel to, that extend along, or that extend in one ormore directions that are not perpendicular to the centerline 126 of theturbomachine 100. As described above, the undulations can help increasethe separation of particles from the fluid.

Optionally, the separator body 1202 may alternatively or additionallyinclude an undulating shape along one or more circumferential directionsof the turbomachine 100. For example, the crests 1208 are shown as beingseparated from each other in the plane of FIG. 12, but additionally oralternatively may be separated from each other in directions that areperpendicular to the plane of FIG. 12. These circumferential directionsmay encircle the centerline 126 of the turbomachine 100. In oneembodiment, the separator body 1202 has undulations only along the innerwall 214 and only along the axial direction of the turbomachine 100. Inanother embodiment, the separator body 1202 has undulations only alongthe inner wall 214 and only along circumferential directions of theturbomachine 100. In another embodiment, the separator body 1202 hasundulations along the inner wall 214 in both the axial andcircumferential directions of the turbomachine 100.

FIG. 13 is a schematic view of an alternative particle separator 1300that may be used with the turbine engine 100 shown in FIG. 1. Theparticle separator 1300 includes a multi-part separator body 1302 thatcan be disposed in the primary fluid passageway 204 described above. Theseparator body 1302 includes the separator body 1202 shown in FIG. 12,but also includes an opposing separator body 1332. The separator body1332 is coupled with the outer wall 212. The separator body 1332 extendsalong the flow path or direction 1212 from an upstream end 1306 to anopposite downstream end 1316. In the illustrated embodiment, the outerwall 212 also includes one or more air bleed holes 1204 that fluidlycouple the primary fluid passageway 204 with another auxiliary fluidpassageway, as described above in connection with the inner wall 214.

The separator body 1332 shown in FIG. 13 has an undulating shape alongthe axial direction 1230. This undulating shape is formed by theseparator body 1332 having several of the crests 1208 and valleys 1210that are spaced apart from each other in the axial direction 1230. Theseparator body 1332 may include the separator openings 1214 to separateparticles from the fluid as the fluid passes between the separatorbodies 1202, 1332. As described above, the undulating surface formed bythe separator body 1332 can increase the efficiency at which particlesare removed from the fluid. While the undulating shape in FIG. 13 showsthe crests 1208 of the separator body 1332 being separated from eachother by valleys 1210 along the axial direction 1230 only, optionally,the separator body 1332 may additionally or alternatively have anundulating shape along the circumferential directions. For example,crests 1208 in the separator body 1332 may be separated from each otherby valleys 1210 along a direction extending into or out of the plane ofFIG. 13 or along a path that encircles the centerline 126 of theturbomachine 100.

Optionally, the separator body 1332 may alternatively or additionallyinclude an undulating shape along one or more circumferential directionsof the turbomachine 100. The particle separators 1200, 1300 may includeone or both separator bodies 1202, 1332 to provide for undulations alongone or both the walls 212, 214, and/or along one or both thecircumferential and/or axial directions.

One or more of the particle separators 1200, 1300 may be retrofitted toan existing turbomachine 100. For example, the turbomachine 100 may bemanufactured and/or used without the particle separator 1200 and/or 1300for one or more duty cycles. The separator bodies 1202 and/or 1332 maythen be added to the walls 212 and/or 214 of the turbomachine 100 foruse in one or more subsequent duty cycles. Alternatively, theturbomachine 100 may be manufactured with the particle separator 1200and/or 1300 included in the turbomachine 100.

An exemplary method 500 of enhancing particle removal from a fluid flowin turbine engine 100 (shown in FIG. 1) is illustrated in the flowdiagram of FIG. 11. With reference to FIGS. 1-10, method 500 includesinducing 502 a fluid flow in turbine engine 100. Method 500 furtherincludes establishing 504 primary fluid flow 216 through primary fluidpassage 204. Also, method 500 includes establishing 506 auxiliary fluidflow 218 through auxiliary fluid passage 206. Establishing 506 auxiliaryfluid flow 218 includes diverting 508 a portion of primary fluid flow216 through fluid diversion passage 228 such that fluid diversionpassage 228 diverts the fluid flow from primary fluid passage 204 toauxiliary fluid passage 206 in a direction opposed to the direction offluid flow through primary fluid passage 204. This diversion can occurby the particle-laden air passing over one or more of the particleseparator devices described herein and a portion of the particle-ladenair passing over and bending around an upstream edge of a separatoropening to direct a filtered portion of the air into the diversionpassage and the auxiliary fluid passage.

In alternative embodiments, fluid diversion passage 228 is first fluiddiversion passage 320 and establishing 506 auxiliary fluid flow 218includes diverting 510 a portion of primary fluid flow 216 through firstfluid diversion passage 320 and second fluid diversion passage 322 suchthat first fluid diversion passage 320 and second fluid diversionpassage 322 diverts the fluid flow from primary fluid passage 204 toauxiliary fluid passage 206 in a direction opposed to the direction offluid flow through primary fluid passage 204.

In other alternative embodiments, establishing 506 auxiliary fluid flow218 includes diverting 512 a portion of primary fluid flow 216 throughfirst fluid diversion passage 420, second fluid diversion passage 422,third fluid diversion passage 424, and fourth fluid diversion passage426 such that first fluid diversion passage 420, second fluid diversionpassage 422, third fluid diversion passage 424, and fourth fluiddiversion passage 426 diverts the fluid flow from primary fluid passage204 to auxiliary fluid passage 206 in a direction opposed to thedirection of fluid flow through primary fluid passage 204.

Particle separating devices described herein provide a cost-effectivemethod for reducing sand particles and/or particulate matter withinsystems (e.g., cooling systems) of turbomachines. Specifically, toreduce particles within the cooling system, the particle separatorsdescribed herein utilize the difference in inertia between particles andair molecules as a separation mechanism. The particle separator islocated over a cooling air extraction hole serving as a particle shieldsuch that particles are restricted from directly entering the coolingpassage. Additionally, the particle separator modifies a cross-sectionalarea of a flow passage, accelerating particle-laden flow therein.Cooling air is routed through a fluid diversion passage within theparticle separator. Particle-laden flow turns approximately 180° at thefluid diversion passage such that particles with higher inertia areseparated and carried downstream. As such, the number of particlestraveling into the cooling passage is substantially decreased. Theparticle separators described herein offer advantages that include,without limitation, cost effective implementation and retro fitapplication. Additionally, the particle separators described herein,have a lower weight than many known particle separators, therebyreducing any weight penalties in an aircraft engine retrofit. Moreover,use of the particle separators describe herein maintain theeffectiveness of cooling systems within turbomachines by reducingparticle accumulation around small features such as rims, film coolingholes, and turbulators, which extends engine component service life, andreduces engine downtime and maintenance costs.

Exemplary embodiments of methods, systems, and apparatus for operatingturbomachines are not limited to the specific embodiments describedherein, but rather, components of systems and/or steps of the methodsmay be utilized independently and separately from other componentsand/or steps described herein. For example, the methods, systems, andapparatus may also be used in combination with other systems requiringreducing particles in a fluid flow, and the associated methods, and arenot limited to practice with only the systems and methods as describedherein. Rather, the exemplary embodiment can be implemented and utilizedin connection with many other applications, equipment, and systems thatmay benefit from separating particles in a fluid flow.

In one embodiment, a particle separator is provided. The particleseparator includes a separator body configured to be disposed in aprimary fluid passageway of a turbomachine that directs aparticle-carrying fluid along a flow path in the primary fluidpassageway toward a combustor of the turbomachine. The primary fluidpassageway of the turbomachine is located between an inner wall and anouter wall that is disposed radially outside of the inner wall from acenterline of the turbomachine. A rotor assembly of the turbomachinerotates around the centerline of the turbomachine. The primary fluidpassageway includes one or more bleed holes through which a divertedportion of the fluid flowing in the primary fluid passageway toward thecombustor is diverted into an auxiliary flow passageway that bypassesthe combustor and directs the diverted portion of the fluid toward oneor more components of the turbomachine that are downstream of thecombustor in the turbomachine. The separator body extends along the flowpath from an upstream end that is configured to be coupled with theinner wall of the primary fluid passageway. The separator body includesat least one upstream edge positioned to separate at least someparticles carried by the fluid from the fluid as the diverted portion ofthe fluid bends around and flows over the at least one upstream edge ofthe separator body and into the auxiliary flow passageway via the one ormore bleed holes while a non-diverted portion of the fluid continues toflow along the flow path in the primary fluid passageway.

Optionally, the separator body is configured to be located in theprimary fluid passageway such that the separator body is disposedradially outward of the one or more bleed holes from the centerline ofthe turbomachine.

Optionally, the separator body has an undulating shape formed of pluralcrests and at least one valley. The crests can be shaped to radiallyextend farther into the primary fluid passageway and radially fartherfrom the inner wall than the at least one valley.

Optionally, the separator body includes one or more separator openingsdisposed between the crests and the at least one valley. Each of the oneor more separator openings can include at least one of the upstreamedges of the separator body.

Optionally, each of the upstream edges of the separator body can bedisposed downstream of a different crest of the crests in the separatorbody.

The separator body can have the undulating shape with the crests alongan axial direction of the turbomachine.

The separator body may have the undulating shape with the crests along acircumferential direction of the turbomachine.

The separator body can have the undulating shape with the crests alongboth an axial direction and a circumferential direction of theturbomachine.

Optionally, separator body has a curved shape along the flow path of thefluid.

Optionally, the separator body can be a radially inward separator body,and the particle separator also can include a radially outward separatorbody configured to be coupled with the outer wall of the primary fluidpassageway. The radially outward separator body can have one or moreundulations.

Optionally, the separator body is shaped to be retrofitted to theprimary fluid passageway of the turbomachine that was previously used tooperate without the separator body in the primary fluid passageway.

In one embodiment, a method includes establishing a fluid flow ofparticle-laden fluid in a primary fluid passageway of a turbomachinethat is defined by an inner wall and a radially outward wall relative toa centerline of the turbomachine, filtering a first portion of theparticle-laden fluid by passing the particle-laden fluid over anundulating separator body having one or more separator openings, that iscoupled with the inner wall of the primary fluid passageway, and thatextends over at least one bleed hole through the inner wall. The firstportion of the particle-laden fluid is filtered by the first portion ofthe particle-laden fluid bending around an edge of the separator body atthe one or more separator openings and flowing into an auxiliary fluidpassageway. A second portion of the fluid passes over the separator bodywithout being filtered by the separator body. The method also includesdirecting the first portion of the fluid that is filtered around acombustor of the turbomachine to one or more downstream components ofthe turbomachine and cooling one or more components of the turbomachineusing the first portion of the fluid while the second portion of the airis directed into the combustor of the turbomachine.

Optionally, filtering the first portion of the fluid includes passingthe fluid over an undulating shape of the separator body.

Optionally, the one or more components of the turbomachine that arecooled include one or more turbine blades.

In one embodiment, a turbomachine includes a compressor sectionconfigured to receive particle-laden fluid and to at least partiallycompress the particle-laden fluid and a primary fluid passageway fluidlycoupled with the compressor section and including opposing inner andradially outward walls. The primary fluid passageway is configured toreceive the particle-laden fluid that is compressed by the compressorsection. The primary fluid passageway includes one or more bleed holesin one or more of the inner wall or the outer wall that are fluidlycoupled with an auxiliary flow passageway. The turbomachine alsoincludes a combustor section fluidly coupled with the compressor sectionby the primary fluid passageway. The combustor section is configured tocombust an unfiltered portion of the particle-laden fluid and formcombustion gases. The turbomachine also includes a turbine sectionfluidly coupled with the combustor section and configured to receive thecombustion gases from the combustor section. The turbine sectionincludes turbine stages configured to be coupled with a rotor sectionand that are configured to be rotated by the combustion gases to rotatethe rotor section. The turbine section also is fluidly coupled with theauxiliary flow passageway. The turbomachine also includes a separatorbody configured to be disposed in the primary fluid passagewaydownstream of the compressor section and upstream of the combustorsection along a flow path of the particle-laden fluid. The separatorbody includes at least one upstream edge positioned to separate at leastsome particles carried from the particle-laden fluid as a divertedportion of the particle-laden fluid bends around and flows over the atleast one upstream edge of the separator body and into the auxiliaryflow passageway via the one or more bleed holes while a non-divertedportion of the particle-laden fluid continues to flow over the separatorbody and along the flow path in the primary fluid passageway to thecombustor section. The auxiliary flow passageway bypasses the combustorsection and directs the diverted portion of the fluid toward the turbinestages via the auxiliary flow passageway.

Optionally, the separator body is configured to be located in theprimary fluid passageway such that the separator body is disposed one ormore of radially outward or radially inward of the one or more bleedholes from the centerline of the turbomachine.

Optionally, the separator body has an undulating shape formed of pluralcrests and at least one valley. The crests are shaped to radially extendfarther into the primary fluid passageway and radially farther from oneor more of the inner wall or the outer wall than the at least onevalley.

Optionally, the separator body includes one or more separator openingsdisposed between the crests and the at least one valley. Each of the oneor more separator openings can include at least one of the upstreamedges of the separator body.

Optionally, each of the upstream edges of the separator body is disposeddownstream of a different crest of the crests in the separator body.

Optionally, the separator body has the undulating shape with the crestsalong one or more of an axial direction or a circumferential directionof the turbomachine.

In one embodiment, a particle separator includes a separator bodyconfigured to be disposed in a primary fluid passageway of a machinethat directs a particle-carrying fluid along a flow path in the primaryfluid passageway toward a volume of the machine. The primary fluidpassageway located between opposing first and second walls. In oneembodiment, these walls circumferentially extend around or encircle acenterline of the machine. Alternatively, these walls oppose each otherwithout circumferentially extend around or encircle a centerline of themachine. For example, these walls may not be disposed in a rotatingmachine or a machine having a centerline. The primary fluid passagewayincludes one or more bleed holes through which a diverted portion of thefluid flowing in the primary fluid passageway is diverted into anauxiliary flow passageway that bypasses the volume and directs thediverted portion of the fluid toward one or more components of themachine that are outside of the volume of the machine. The separatorbody extends along the flow path from an upstream end that is configuredto be coupled with the inner wall of the primary fluid passageway. Theseparator body includes at least one upstream edge positioned toseparate at least some particles carried by the fluid from the fluid asthe diverted portion of the fluid bends around and flows over the atleast one upstream edge of the separator body and into the auxiliaryflow passageway via the one or more bleed holes while a non-divertedportion of the fluid continues to flow along the flow path in theprimary fluid passageway.

Optionally, the separator body is configured to be located in theprimary fluid passageway such that the separator body is disposedoutward of the one or more bleed holes and between the first and secondwalls.

Optionally, the separator body has an undulating shape formed of pluralcrests and at least one valley, the crests shaped to radially extendfarther into the primary fluid passageway and farther from the firstwall than the at least one valley.

Optionally, the separator body includes one or more separator openingsdisposed between the crests and the at least one valley, each of the oneor more separator openings including at least one of the upstream edgesof the separator body.

Optionally, each of the upstream edges of the separator body is disposeddownstream of a different crest of the crests in the separator body.

Optionally, the separator body has the undulating shape with the crestsalong an axial direction of the machine.

Optionally, the separator body has the undulating shape with the crestsalong a first direction.

Optionally, the separator body has the undulating shape with the crestsalong both first and second orthogonal directions.

Optionally, the separator body has a curved shape along the flow path ofthe fluid.

Optionally, the separator body is a first separator body that is coupledwith the first wall. The separator also can include a second separatorbody configured to be coupled with the second wall of the primary fluidpassageway. The second separator body has one or more undulations.

Optionally, the separator body is shaped to be retrofitted to theprimary fluid passageway of the machine that was previously used tooperate without the separator body in the primary fluid passageway.

In one embodiment, a method includes establishing a fluid flow ofparticle-laden fluid in a primary fluid passageway of a machine that isdefined by opposing first and second walls. These walls maycircumferentially extend around or encircle the centerline of a machinehaving one or more rotating component. Alternatively, the walls may notcircumferentially extend around or encircle the centerline of such amachine, the machine may not have a centerline, or the machine may nothave a rotating component. The method also can include filtering a firstportion of the particle-laden fluid by passing the particle-laden fluidover an undulating separator body having one or more separator openingsthat extends over at least one bleed hole through the first wall. Thefirst portion of the particle-laden fluid is filtered by the firstportion of the particle-laden fluid bending around an edge of theseparator body at the one or more separator openings and flowing into anauxiliary fluid passageway. A second portion of the fluid passes overthe separator body without being filtered by the separator body. Themethod also includes directing the first portion of the fluid that isfiltered to one or more downstream components of the machine.

Although specific features of various embodiments of the disclosure maybe shown in some drawings and not in others, this is for convenienceonly. In accordance with the principles of the disclosure, any featureof a drawing may be referenced and/or claimed in combination with anyfeature of any other drawing.

This written description uses examples to disclose the embodiments,including the best mode, and to enable any person skilled in the art topractice the embodiments, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe disclosure is defined by the claims, and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they have structural elementsthat do not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal language of the claims.

What is claimed is:
 1. A method comprising: establishing a fluid flow ofparticle-laden fluid in a primary fluid passageway of a machine that isdefined by opposing first and second walls; filtering a first portion ofthe particle-laden fluid by passing the particle-laden fluid over anundulating separator body having one or more separator openings thatextends over at least one bleed hole through the first wall, the firstportion of the particle-laden fluid filtered by the first portion of theparticle-laden fluid bending around an edge of the separator body at theone or more separator openings and flowing into an auxiliary fluidpassageway, wherein a second portion of the fluid passes over theseparator body without being filtered by the separator body; anddirecting the first portion of the fluid that is filtered to one or moredownstream components of the machine.
 2. The method of claim 1, whereinfiltering the first portion of the fluid includes passing the fluid overan undulating shape of the separator body.
 3. The method of claim 1,wherein the one or more components of the machine to which the firstportion of the fluid is directed include one or more turbine blades. 4.The method of claim 1, wherein filtering the first portion of the fluidincludes passing the fluid over plural crests and at least one valley ofthe separator body, wherein the fluid is passed over the crests thatextend farther into the primary fluid passageway and farther from thefirst wall than the at least one valley.
 5. The method of claim 1,wherein filtering the first portion of the fluid includes passing thefluid over the separator body in the primary fluid passageway inlocations that are outward of the one or more bleed holes and betweenthe first and second walls.
 6. A particle separator comprising: aseparator body configured to be disposed in a first fluid passageway ofa machine that directs a fluid carrying particles along a flow path inthe first fluid passageway, the separator body including pluralundulating sections separated from each other by diversion passages, theundulating sections of the separator body positioned to separate adiverted portion of the fluid from a particle-carrying portion of thefluid, the diverted portion of the fluid flowing around and through thediversion passages to a second fluid passageway of the machine while theparticle-carrying portion of the fluid flowing over the separator body,past the diversion passages, and continuing to flow in the first fluidpassageway.
 7. The particle separator of claim 6, wherein the separatorbody is disposed between an inner wall and an outer wall of the firstfluid passageway, and each of the undulating sections of the separatorbody includes opposite upstream and downstream ends with the upstreamend located closer to the inner wall of the first fluid passageway thanthe downstream end.
 8. The particle separator of claim 7, wherein theundulating sections include at least an upstream undulating section anda downstream undulating section, the upstream undulating section havingthe upstream end that is closer to the inner wall than the upstream endof the downstream undulating section.
 9. The particle separator of claim7, wherein the undulating sections include at least an upstreamundulating section and a downstream undulating section, the upstreamundulating section having the downstream end that is closer to the innerwall than the downstream end of the downstream undulating section. 10.The particle separator of claim 7, wherein the undulating sectionsinclude at least an upstream undulating section and a downstreamundulating section, the upstream undulating section having thedownstream end that is farther from the inner wall than the upstream endof the downstream undulating section.
 11. The particle separator ofclaim 6, wherein each of the undulating sections of the separator bodyhas an S-shape.
 12. The particle separator of claim 6, wherein theseparator body is disposed between an inner wall and an outer wall ofthe first fluid passageway, and the separator body includes an elongatedflow member disposed between the outer wall of the first fluidpassageway and the undulating sections of the separator body.
 13. Theparticle separator of claim 6, wherein the separator body is disposedbetween an inner wall and an outer wall of the first fluid passagewaywith an upstream end of the separator body sealed to the inner wall, anopposite downstream end of the separator body sealed to the inner wall,but none of the undulating sections of the separator body sealed toeither the inner wall or the outer wall.
 14. The particle separator ofclaim 6, wherein the undulating sections of the separator body areseparated from each other by the diversion passages along an axialdirection of the machine.
 15. The particle separator of claim 6, whereinthe undulating sections of the separator body are separated from eachother by the diversion passages along a circumferential direction of themachine.
 16. A particle separator comprising: a multi-part separatorbody configured to be disposed in a first fluid passageway of a machinethat directs a fluid carrying particles along a flow path in the firstfluid passageway between a radially inner wall and a radially outer wallof the first fluid passageway, the multi-part separator body including aradially inward group of undulating sections and a radially outer groupof the undulating sections, the undulating sections in each of theradially inward group and the radially outer group separated from eachother by diversion passages shaped to separate diverted portions of thefluid from a particle-carrying portion of the fluid, the divertedportions of the fluid flowing around and through the diversion passagesin the radially inward group to a second fluid passageway of the machineand flowing around and through the diversion passages in the radiallyouter group to a third fluid passageway of the machine while theparticle-carrying portion of the fluid flows between the radially inwardgroup and the radially outer group, past the diversion passages, andcontinues to flow in the first fluid passageway.
 17. The particleseparator of claim 16, wherein each of the undulating sections in theradially inward group includes opposite upstream and downstream endswith the upstream end located closer to the inner wall of the firstfluid passageway than the downstream end.
 18. The particle separator ofclaim 16, wherein each of the undulating sections in the radially outergroup includes opposite upstream and downstream ends with the upstreamend located closer to the outer wall of the first fluid passageway thanthe downstream end.
 19. The particle separator of claim 16, wherein eachof the undulating sections has an S-shape.
 20. The particle separator ofclaim 16, wherein an upstream end and a downstream end of the radiallyinward group of the undulating sections is sealed to the inner wall andan upstream end and a downstream end of the radially outer group of theundulating sections is sealed to the outer wall.